Son-in-law cancels family vacation after his parents took over planning and tried to exclude his in-laws: 'I wasn't going to exclude my wife's family to keep them happy.'

Why can't they just go with the flow and have fun on the vacation? 

It's incredibly logistically difficult to go on a large family vacation. There's a reason a lot of families don't travel with their grandparents, aunts, uncles, and the works: it's so hard to get everyone to agree on everything. Grandma and grandpa probably have a harder time getting around than Uncle Steve, who wants to go on a river rapids adventure. Parents with young kids probably want to do different activities than parents with older kids. Everyone has a different idea of how much they want to pay and what they want to do. It's literally impossible to make everybody happy, which is why it's much easier to limit everything to a smaller group. 

The same principle applies to any kind of social gathering! It's the easiest thing in the world to plan to go to the movie theater with your best friend, but if you include your best friend's girlfriend, her two friends, their partners, and their partners' best friends, it starts to get complicated. Girls' trips and boys' trips exist for a reason! It's logistically easier to plan with your friend than with your friends and their partners. People might feel bad about being excluded, but you literally can't invite every friend to every social event, and that's good! Having more intimate gatherings lets you spend more one-on-one time with the people you value most.

Of course, it's understandable to want to try your hardest to include everyone in your good times, but that's not always possible. The couple in this story tried to best include both sets of parents in their vacation, but his parents just weren't having it.